Vernor Vinge is not a man who hurries, and The Children of the Sky is a book that, on every page, feels like a story long in the making. I suppose that's a general truism when a novel's sequel is released nearly twenty years later. Like A Fire Upon the Deep, Children is a lavishly imagined and densely constructed adventure. It lacks the galaxy-spanning scope of Fire, as well as that book's seemingly unstoppable rush of conceptual awesomeness. But it compensates with superior attention to character and a plot that offers intriguing thematic insights into political paranoia and division. It is its own book, paying homage to its predecessor without merely rehashing it, and demands such attention from the reader that I did something I've never done before: I read it twice before writing this review.

The ending of A Fire Upon the Deep left Ravna Bergsndot stranded on the Tines world with human children Johanna and Jefri Olsndot, among a society of lupine beings in which a pack of several individuals must pool their consciousnesses to establish a single identity. The Tines are, now as in the original, among the most imaginatively conceived of alien races. Vinge uses this novel, set entirely on their world, to explore and expand upon them to often brilliant effect. The result is the story of a young culture in the midst of, to put it mildly, growing pains.

A decade has passed since the events of Fire. Ravna is the de facto leader of the colony of now-grown human children stranded while fleeing the implacable destruction of the Blight. The triggering of the Countermeasure, the one weapon capable of fending off this menace, has only bought the Tines world some time. Unfortunately, Ravna has not anticipated that, during the years she's been focusing on the Blight as the main threat, her young charges have been splitting into factions.

A sizable number of the Children not only deny the very existence of the Blight, but consider Ravna a fanatical autocrat whose stories and endless warnings about it are simply lies to mask her role in destroying what can only have been very valuable research by the Children's parents. Moreover, they see her obsessions as a hindrance to more immediate problems, like life extension. They miss the high-tech luxuries of their homeworld, and resent the lack of them in this barely-industrial alien society. Ravna's discovery of the Denier movement among the Children hits her like a mule kick. It has never occurred to her to think of herself as a political naïf. And she's utterly unprepared to find herself outmaneuvered by Nevil Storhorte, an assumed ally who reveals himself to be a natural-born political manipulator, as charismatic as he is dishonest and sociopathic.

There is more than a little tension between the Tines as well. Woodcarver continues to rule the Domain, after the victory against Steel in Fire. But Woodcarver is now a moody and erratic leader, with a new pup (amusingly nicknamed "Little Sht") among its pack affecting its overall attitude, causing a strained relationship with Ravna. The dastardly Vendacious, who has perhaps the best villain name in all of SF this side of Darth Maul, has made his way to a neighboring territory. After scheming with Nevil to discredit Ravna and remove her from power, Vendacious has been cutting deals with a pompous Tine industrialist named Tycoon to take back the Domain. Vinge has a whale of a time writing Tycoon, squeezing every drop of effete, pretentious arrogance out of the character he can. He's the kind of bad guy you don't love to hate, but just love. Tycoon — who's managed to expand his pack to an unprecedented 12 — has been working to harness the aid of unusual, non-pack Tines from the Tropics called the Choir. (Lacking packs, the whole bunch of them are like a psychic mob.) Vendacious hopes to utilize technology — not only from Ravna's spaceship, now seized by Nevil, but newly developed tech like radio cloaks that allow a single pack to spread itself over a greater distance — in his rise to power.

Like Fire, Children spends a lot of time as a chase story. Ravna is beset with abductions, betrayals, intrigues, and what amounts to a full-on revolution. It's something of a chore to follow. But Vinge's command of character is so much stronger here. As the story throws our heroes into greater and greater perils, we bond with them that much more. There are moments of humor that the original didn't quite have, as well. At one point, while fleeing enemies in the forested wilderness, Ravna, Jefri and their party must pretend to be something like a traveling circus act. This presents Jefri's Tine companion Amdi, perpetually timid and childish, with his first moments of growth and courage as he has to take charge and play a commanding role for the sake of their survival.

In the end, you realize that the story here is really no less epic in its ambitions than Fire. It is simply that this time, Vinge's focus is inwards. It's a story about how ego and ambition will often cause, not just a person, but entire populations, to work actively against their own best interests. Are we even capable of letting go of our own infighting and personal vendettas long enough to address problems that face us all? Readers who love absurdly intricate tales of political intrigue and skullduggery will find much to impress them, but you won't be left wanting if your love is good old action-adventure either. The book is not its predecessor, but that's its strength. The Zones of Thought novels began as one kind of story (tech-savvy space opera) and now continue as another (anthropologically and politically savvy planetary romance), with each belonging seamlessly to the other. Vernor Vinge's ability to bring so much more storytelling range and intellectual insight into continuing this monumental saga is what makes him one of SF's most vital novelists.